In a rotary actuator comprising a housing containing a piston and having a cover and a base, thread-like guide grooves in the piston, a shaft having a transverse axis and being rotatable about an axis of the rotary actuator which transverse axis engages into the guide grooves, and torque support engaging into guides in the piston, which torque supports are anchored in the housing, wherein the transverse axis on both ends comprises bushes contacting raceways of the guide grooves, each bush is cambered and each raceway is configured with an undercut corresponding to the cambering.

In a rotary drive with a housing that contains a piston, a lid and a bottom, screw thread-like guiding grooves in the piston, a shaft with a rotary axis that can be rotated around an axis of the rotary drive and that encroaches in the guiding grooves, and axially parallel torque supports that are attached in the lid and/or bottom and that are embedded in guidances in the piston, with each torque support having an approximately rectangular external cross-section with a load-specific design to support torques to be transmitted and having longer rectangle sides tangentially to the shaft and shorter rectangle sides approximately in directions towards the axis.

A rotary actuator is provided. The rotary actuator includes a stator assembly centered along a longitudinal axis of the rotary actuator. The rotary actuator also includes a rotor assembly surrounding the stator assembly. The rotor assembly is rotatable about the longitudinal axis relative to the stator assembly. The rotary actuator also includes first and second bearing assemblies mounted at adjacent opposed axial ends of the stator assembly and connected between the stator assembly and rotor assembly to allow for the rotation of the rotor assembly about the longitudinal axis relative to the stator assembly. A hydraulic actuation arrangement is formed between the rotor assembly and the stator assembly. The hydraulic actuation arrangement includes at least one first pressure chamber and at least one second pressure chamber. At least one of the at least one first pressure chamber and the at least one second pressure chamber has a variable volume.

An artificial lift system can include an actuator operable to reciprocate a rod string in the well, the actuator including a piston reciprocably disposed in a cylinder, and a piston rod connected to the piston, and a rod rotator that continuously rotates the piston rod relative to the cylinder as the piston displaces in a longitudinal direction relative to the cylinder. A method of rotating a rod string can include connecting the rod string to a piston rod of an actuator, longitudinally reciprocating the piston rod relative to a cylinder of the actuator and a mandrel of a rod rotator, and rotating the piston rod relative to the mandrel in response to the reciprocating, the mandrel being disposed at least partially within the piston rod during the rotating. A rod rotator can include a mandrel having a helical external profile configured to attach to a cylinder of a hydraulic actuator, an internal profile complementarily shaped relative to the external profile, and a one-way clutch.

Combination linear and rotary actuators are disclosed. The linear and rotary actuators have a housing defining a cylindrical interior space and a pair of pistons located inside the cylindrical interior space. An inner bearing cylinder is provided that has spaced-apart ball bearings arranged in a helical pattern on its surface that engage with a structure having an inner surface with helical grooves therein. The structure at least indirectly engages a linear drive piston that is slidably mounted in the housing, and provides rotational movement thereto. The linear drive piston has an input shaft that has ball bearings on its surface, and is inserted inside the output shaft of a revolution piston that has an inner surface with linear grooves. The actuators use hydrostatically charged integral bearing races that activate during operation to reduce friction. Combination linear and rotary actuators with double actuation output shafts are also provided.

Combination linear and rotary actuators are disclosed. The linear and rotary actuators have a housing defining a cylindrical interior space and a pair of pistons located inside the cylindrical interior space. An inner bearing cylinder is provided that has spaced-apart ball bearings arranged in a helical pattern on its surface that engage with a structure having an inner surface with helical grooves therein. The structure at least indirectly engages a linear drive piston that is slidably mounted in the housing, and provides rotational movement thereto. The linear drive piston has an input shaft that has ball bearings on its surface, and is inserted inside the output shaft of a revolution piston that has an inner surface with linear grooves. The actuators use hydrostatically charged integral bearing races that activate during operation to reduce friction. Combination linear and rotary actuators with double actuation output shafts are also provided.

A rotary actuator for a hinged panel assembly, e.g., of a fixed-wing aircraft, includes ball bearings, an outer cylinder, a piston, and an inner shaft. The outer cylinder admits fluid pressure from a fluid pressure supply. The piston is circumscribed by the outer cylinder. The piston, outer cylinder, and ball bearings collectively forming an outer ball screw. The piston translates along a longitudinal center axis in response to the fluid pressure. The inner shaft is circumscribed by the piston, with the inner shaft, piston, and ball bearings collectively forming an inner ball screw that is concentric with the outer ball screw. The ball screws form an interlaced ball circuit with one or more shared ball paths. Piston translation rotates the piston and inner shaft, and to thereby recirculates the ball bearings between the outer ball screw and the inner ball screw through the interlaced ball circuit.

A rotary actuator for a hinged panel assembly, e.g., of a fixed-wing aircraft, includes ball bearings, an outer cylinder, a piston, and an inner shaft. The outer cylinder admits fluid pressure from a fluid pressure supply. The piston is circumscribed by the outer cylinder. The piston, outer cylinder, and ball bearings collectively forming an outer ball screw. The piston translates along a longitudinal center axis in response to the fluid pressure. The inner shaft is circumscribed by the piston, with the inner shaft, piston, and ball bearings collectively forming an inner ball screw that is concentric with the outer ball screw. The ball screws form an interlaced ball circuit with one or more shared ball paths. Piston translation rotates the piston and inner shaft, and to thereby recirculates the ball bearings between the outer ball screw and the inner ball screw through the interlaced ball circuit.

A stepper motor driven actuator system is provided. The system includes a stepper motor, a cam, and a gearbox system. The gearbox system operatively connects the stepper motor to the cam. The cam rotates in response to stepping of the stepper motor. The system also includes a valve having a control piston located therein. The control piston is configured to translate in response to rotation of the cam. The system further includes a rotary actuator. The rotary actuator is fluidly connected to the valve, and the rotary actuator is configured to rotate the cam in response to translation of the control piston.

A rotary joint, including: a hydraulic follow-up mechanism and a rotary transmission mechanism. The hydraulic follow-up mechanism includes a cylinder body, a valve sleeve, a valve core, a valve body, a left end cover and a right end cover. The rotary transmission mechanism includes a tray, a stabilizing ring, a follow-up disk, a torque transfer disk and a stable supporting wheel mechanism. The left end cover and the right end cover are arranged at the left and right ends of the cylinder body, respectively. The valve body is concentrically mounted in a cylindrical hollow chamber of the cylinder body. The output shaft at the right end of the valve body projects out of the right end cover. The right end of the valve core is provided with a valve core torque transfer shaft extending rightwards through the right end of the valve body.